MOSCOW, March 20 (Reuters) - Russia laid out conditions on Monday for agreeing to any further extension of the Black Sea grain deal, and President Vladimir Putin said that Moscow could send free grain to African countries if those conditions were not met. It said the deal's renewal in May would depend on certain conditions, including the restoration of access to the SWIFT financial messaging system for Russian state-owned agriculture-focused bank Rosselkhozbank, a resumption of farm machinery supplies, and the unblocking of foreign assets and accounts held by Russian agricultural companies. See here for a complete list of exchanges and delays